Annual report pursuant to Section 13 and 15(d)

Income Taxes, Tax Credits and Unrecognized Tax Benefits (Details)

v3.6.0.2
Income Taxes, Tax Credits and Unrecognized Tax Benefits (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Reconciliation of the total amounts of unrecognized tax benefits [Roll Forward]      
Balance at January 1 $ 4.7 $ 4.8 $ 6.0
Gross Increases - Tax Positions Prior Periods 0.3 0.4 0.5
Gross Decreases - Tax Positions Prior Periods (0.4) (0.1) (0.4)
Gross Increases - Current Period Tax Positions 0.5 0.5 0.7
Decreases - Settlements with Taxing Authorities 0.0 (0.6) (0.7)
Reductions - Lapse of Statute of Limitations (1.7) 0.0 (1.2)
Other 0.0 (0.3) (0.1)
Balance at December 31 3.4 4.7 4.8
Gross Unrecognized Tax Benefits, Including Interest 3.5 4.8 $ 5.1
Possible Decrease in Unrecognized Tax Benefits in 2017 1.1    
Tax Credit Carryforward [Line Items]      
Tax Credit Carryforward, Amount 49.5    
Tax Credit Carryforwards 47.3 $ 57.0  
Tax Credit Carryforward, Expiration Date 49.3    
Tax Credit Carryforwards, Not Subject to Expiration 0.2    
General Business Credits [Member]      
Tax Credit Carryforward [Line Items]      
Tax Credit Carryforwards 11.1    
State Tax Credits [Member]      
Tax Credit Carryforward [Line Items]      
Tax Credit Carryforwards $ 38.4